The use of robots with gripping devices comprising a plurality of rods and a plurality of suction cups arranged in said rods for stacking parts is known. For stacking parts of different shapes and sizes, the gripping device must be adapted to the shape of the part.
It is known that a gripping device must be provided for each type of part to be manipulated and the arm must be changed according to the part to be manipulated.
In addition, gripping devices comprising a drive for each rod or suction cup such that the rods or suction cups can be moved by means of said drives are known. The drawback of such gripping devices is that the arm is very heavy and therefore cannot work at high speeds.
DE3504586A1 discloses a flexible manipulator arm comprising two rods and a plurality of gripping elements with respective suction cups arranged on said rods. Each gripping element comprises a blocking/unblocking element that retains said gripping element in the desired position and releases the gripping element so that it can move in the corresponding rod when it is to be positioned. For positioning the gripping elements in the rods, the positioning system comprises means for retaining the gripping element to be positioned.
US2009/0194922A1 discloses a flexible gripping device coupled to a robot manipulator comprising a plurality of supporting arms and a plurality of gripping elements attached to said supporting arms, each gripping element comprising a respective suction cup. The gripping elements are movable with respect to the respective supporting arm, each supporting arm comprising at least one guiderail and each movable gripping element comprising a carriage movable in the corresponding guiderail. The flexible gripping device comprises a blocking/unblocking bolt, which has to be loosen in order to position a gripping element in the corresponding guiderail and tighten to retain a gripping element in the corresponding guiderail.